Manufacture of threads of any thickness from viscose



Patented Sept. 23, 1924.

PATENT .OFFICE.

EMILE BRONNERT, Oli MULHOUSE, FRANCE.

MANUFACTURE OF THREADS OF ANY THICKNESS FROM VISCOSE. I

No Drawing.

To all whom it may concern:

Be it known that I, EMILE BRONNE'RT, a citizen of the Republic of France, residing at Mulhouse, France, have invented certain new and useful Improvements in the Mannfacture of Threads of any Thickness from Viscose (for which I filed an application in Germany on Nov. 15, 1920) and I do hereby declare the following to be a full, clear, and exact description of the invention.

The present invention relates to an improvement in the process for the direct manufacture of finest viscose. silk, disclosed in my Patent No. 1,393,198, dated October 11, 1921. J

Said patent shows that viscose silk threads of predetermined fineness can be produced by treatingviscose in a coagulating bath containing a salt, and an acid, the minimum proportion of the latter to the whole being approximately inversely proportional to the square root of the thread size. It is tacitly understood that normally ripened cellulose of 8-9 degrees of ripeness (ammonium chlorid measure) and customary openings of 0.10 mm. in diameter, a normal speed of spinning of from 40 to 50 metres per minuteand a suitable temperature for the bath of from 40 to 50 degrees centigrade are emplo ed. p

ow viscose of 8-9 degrees of ripeness cannot always be employed. Often it is necessary to use crude viscose of any kind or composition and varying consistency, and in the spinning of viscose of varying consistencies and viscose containing admixtures, it has proven advantageous to make use of spin- 1 ning apertures of different diameters, these being chosen of larger diameter according as, for some reason or other, the Viscose to be treated has a higher degree of consistency, that is to say, is more viscous.

Elaborate experiments have now strikingly demonstrated that the general squareroot law as it is called, which, starting from the minimum acid concentration of a spinning bath at which a given viscose faultlessly spins a fibre of a specified-thickness, enables the necessary minimum concentration to be determined which will lead to the equally faultless spinning of the same ployed.

Application filed November 17, 1921. SerialNo. 515,990.

Apart from the fact that not only the percentage of free sulphuric acid present but also a possible addition of an ammonium salt (which as is known, acts like an acid in the presence of the fixed alkali of the viscose), or of sulphurous or some other acid must be taken 'into account, the result attained was that the total amount of acid present or substances acting like acids in this case must be fixed higher in proportion as the nozzle cross section is greater than that mostly in use, namely 0.1 mm., or must be fixed lower, speaking absolutely, in proportion as the nozzle cross section may or must be chosen smaller than the latter. If a smaller cross section be adopted, then only a smaller degree of acidity of the spinning bath is necessary. lit may be said that, taking the above given rules into consideration, all known additions to the spinning bath, as glucose, oxy-fatty acids, polyatomic alcohols or the like may be made withoutimpairing the technical spinning operations. This circumstance however is of substantial technical value, more especially in the case of the very finest fibres, where the danger is greater than in other cases that the thread of regenerated cellulosewould be parchmentized,

owing to the action of the necessary stronger acid.

the operation proceeds smoothly.

(b) If however, the same denier has to be spun from an aperture of 0.12 mm. diameter, then the entire precipitative power must be about higher and the composition of the bath must be for instance 150 grammes H SO +300 grammes (NH,,) SO,+300 grammes Na SO, per litre.

Since, as is well known, the thread-formative action of ammonium sulphate is to that of sulphuric acid in about the ratio of 1:2, it follows that a bath having for its minimum concentration that represented by 200 grammes H SO,+200 grammes (NH So t-300 grammes Na,.SO per'litre would lead to the same result.

. diameter, then the precipitative power (a) If the same litre of 3 deniers is to be spun from an aperture of only 0.08 mm. may be less than under (a). A bath'with a minimum concentration represented by:

70 rammes H SO,+14O grammes (NH O f-300 grammes N a- SO, per litre will lead directly and without hitch a the end desired. Another part of the sulphuric acid may be appropriately replaced by ammonium sulphate as follows 100 grammes H SO +80 to 100 grammes (NH SO,+300 grammes Na SO per litre; or Y 5O rammes h SO +180 to 200 grammes (NI-I ,s0,+300 grammes Na SO, per litre. In order to make clear these proportions the following table will give at a glance the relations of sulphuric acid and ammonium sulphate:

Diameter of Spinning 2 denier Spmnmgfi denier gig aper' threads. threads.

Grams per liter. Grams per liter. 0.5;. 130 1;. H1504 or 80 g. 11,804+

100 E. 11102 4 0.8 180 g. H130 140 g. HzSO4 or or 90 g. H1SO g. H2S04+ 180 g. (NH4):SO4 180-200 g. (NHDZSOA 70 g. HzSOri- 140 g. (NHOzSOa or 100 g. HnSOrl 190 g. (NH|)|S04 0.10 270 g. H1504 200 3. H1804 or or 150 g. HzSOrl 100 H2304 240 g. (NH4)2SO| 200 g (NHmSO; 0.12 300 g 1804 150 g. HrSOrl 300 g.'(NH4)1S04 or 200 g. HaS ri- 200 g. (NHdzSOa In the case of viscose having a different degree of viscosity or some other composition or a. different dispersivity and in the case also of viscose containing such additions as glucose or the degradation products of cellulose or sulphites or sulphates or further quantities of fixed or volatile alkalies or the like, the minimum concentration of the bath, taken as a starting point, for a given ltitre, a iven speed of drawing, a given length 0 the passage in the spinning ath and" a given temperature, must, it need hardly be said, be determined for each special case.

I claim:

1. The process of producing viscose threads of any desired fineness from raw viscose, which comprises forcing the viscose through suitable'openings into an acid precipitating bath containing sulphuric acid, the concentration of which bath is increased proportionately to the increase in fineness of the thread desired to be produced and to the increase in the size of the openings through which the viscose is forced, and in which part of the sulphuric acid is replaced by double its weight of ammonium sulphate.

2. The process of producing viscose threads of any desired fineness from raw viscose, which comprises forcing the viscose through suitable openings into a sulphuric acid precipitating bath the concentration of which is increased proportionately to the increase of the fineness of the thread desired to be produced and to the increase in the size of the openings through which the viscose is forced, and in which a part of the sulphuric acid is replaced by double the weight of ammonium sulphate and which 'also contains a compound beneficial to the precipitation.

3. The process of producin viscose threads of any desired fineness rom raw viscose, which comprises forcing the viscose through suitable openings into a sulphuric acid precipitating bath the concentration of which is increased proportionally to the increase of the fineness of the thread desired to be produced and to the increase in the size of the openin s through which the viscose is forced, and in which a part of the sulphuric acid is replaced by double the weight of ammonium sulphate and which also contains a salt beneficial to the precipitation.

4. The process of producin viscose threads ofany desired fineness rom raw viscose which comprises forcing the viscose through suitable openin s into a sulphuric acid precipitating bath the concentration of which is increased proportionally to the increase of the fineness of the thread desired to be produced and to the increase in the size of the openin s through which the viscose is forced, an in which a part of the sulphuric acid is replaced by ,double the weight of ammonium sulphate and which also contains a sulphate beneficial to the precipitation.

In testimony that I claim the foregoing as my invention, I have signed in name.

EMILE BRO N ERT.

Witnesses: I

L. D. AUTHEVILLE, A. BRONNERT. 

